- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- BUGS
- RETURN VALUES
- SEE ALSO
- HISTORY

# NAME

X509_STORE_CTX_new, X509_STORE_CTX_cleanup, X509_STORE_CTX_free, X509_STORE_CTX_init, X509_STORE_CTX_trusted_stack, X509_STORE_CTX_set_cert, X509_STORE_CTX_set_chain, X509_STORE_CTX_set0_crls, X509_STORE_CTX_get0_param, X509_STORE_CTX_set0_param, X509_STORE_CTX_set_default - X509_STORE_CTX initialisation

# SYNOPSIS

     #include <openssl/x509_vfy.h>

     X509_STORE_CTX *X509_STORE_CTX_new(void);
     void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx);
     void X509_STORE_CTX_free(X509_STORE_CTX *ctx);

     int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store,
                             X509 *x509, STACK_OF(X509) *chain);

     void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk);

     void   X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx,X509 *x);
     void   X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx,STACK_OF(X509) *sk);
     void   X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk);

     X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx);
     void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param);
     int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name);

# DESCRIPTION

These functions initialise an X509_STORE_CTX structure for subsequent use by X509_verify_cert().

`X509_STORE_CTX_new()` returns a newly initialised X509_STORE_CTX structure.

`X509_STORE_CTX_cleanup()` internally cleans up an X509_STORE_CTX structure. The context can then be reused with an new call to X509_STORE_CTX_init().

`X509_STORE_CTX_free()` completely frees up ctx. After this call ctx is no longer valid.

`X509_STORE_CTX_init()` sets up ctx for a subsequent verification operation. It must be called before each call to X509_verify_cert(), i.e. a ctx is only good for one call to X509_verify_cert(); if you want to verify a second certificate with the same ctx then you must call `X509_STORE_CTX_cleanup()` and then `X509_STORE_CTX_init()` again before the second call to X509_verify_cert(). The trusted certificate store is set to store, the end entity certificate to be verified is set to x509 and a set of additional certificates (which will be untrusted but may be used to build the chain) in chain. Any or all of the store, x509 and chain parameters can be NULL.

`X509_STORE_CTX_trusted_stack()` sets the set of trusted certificates of ctx to sk. This is an alternative way of specifying trusted certificates instead of using an X509_STORE.

`X509_STORE_CTX_set_cert()` sets the certificate to be vertified in ctx to x.

`X509_STORE_CTX_set_chain()` sets the additional certificate chain used by ctx to sk.

`X509_STORE_CTX_set0_crls()` sets a set of CRLs to use to aid certificate verification to sk. These CRLs will only be used if CRL verification is enabled in the associated X509_VERIFY_PARAM structure. This might be used where additional ``useful'' CRLs are supplied as part of a protocol, for example in a PKCS#7 structure.

X509_VERIFY_PARAM *X509_STORE_CTX_get0_param() retrieves an intenal pointer to the verification parameters associated with ctx.

`X509_STORE_CTX_set0_param()` sets the intenal verification parameter pointer to param. After this call param should not be used.

`X509_STORE_CTX_set_default()` looks up and sets the default verification method to name. This uses the function `X509_VERIFY_PARAM_lookup()` to find an appropriate set of parameters from name.

# NOTES

The certificates and CRLs in a store are used internally and should not be freed up until after the associated X509_STORE_CTX is freed. Legacy applications might implicitly use an X509_STORE_CTX like this:

      X509_STORE_CTX ctx;
      X509_STORE_CTX_init(&ctx, store, cert, chain);

this is not recommended in new applications they should instead do:

      X509_STORE_CTX *ctx;
      ctx = X509_STORE_CTX_new();
      if (ctx == NULL)
            /* Bad error */
      X509_STORE_CTX_init(ctx, store, cert, chain);

# BUGS

The certificates and CRLs in a context are used internally and should not be freed up until after the associated X509_STORE_CTX is freed. Copies should be made or reference counts increased instead.

# RETURN VALUES

`X509_STORE_CTX_new()` returns an newly allocates context or NULL is an error occurred.

`X509_STORE_CTX_init()` returns 1 for success or 0 if an error occurred.

`X509_STORE_CTX_get0_param()` returns a pointer to an X509_VERIFY_PARAM structure or NULL if an error occurred.

X509_STORE_CTX_cleanup(), X509_STORE_CTX_free(), X509_STORE_CTX_trusted_stack(), X509_STORE_CTX_set_cert(), X509_STORE_CTX_set_chain(), `X509_STORE_CTX_set0_crls()` and `X509_STORE_CTX_set0_param()` do not return values.

`X509_STORE_CTX_set_default()` returns 1 for success or 0 if an error occurred.

# SEE ALSO

X509_verify_cert X509_VERIFY_PARAM_set_flags

# HISTORY

`X509_STORE_CTX_set0_crls()` was first added to OpenSSL 1.0.0